SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '434ae598f76ab3ccc58c71108a2fc45534a2bc64d35d4d799a005af50fd15d99' 
  AND token = 'b0jHm42Z5YJ6q+D+WDQuBlUUd4ahbOFDHN/MHggL/7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}